Production and detection of relic gravitons in quintessential inflationarymodels - art. no. 123511

Authors
Citation
M. Giovannini, Production and detection of relic gravitons in quintessential inflationarymodels - art. no. 123511, PHYS REV D, 6012(12), 1999, pp. 3511
Citations number
79
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW D
ISSN journal
0556-2821 → ACNP
Volume
6012
Issue
12
Year of publication
1999
Database
ISI
SICI code
0556-2821(199912)6012:12<3511:PADORG>2.0.ZU;2-3
Abstract
A large class of quintessential inflationary models, recently proposed by P eebles and Vilenkin, leads to post-inflationary phases whose effective equa tion of state is stiffer than radiation. The expected gravitational wave lo garithmic energy spectra are tilted towards high frequencies and characteri zed by two parameters: the inflationary curvature scale at which the transi tion to the stiff phase occurs and the number of (nonconformally coupled) s calar degrees of freedom whose decay into fermions triggers the onset of a gravitational reheating of the Universe. Depending upon the parameters of t he model and upon the different inflationary dynamics (prior to the onset o f the stiff evolution), the relic gravitons energy density can be much more sizable than in standard inflationary models, for frequencies larger than 1 Hz, py,estimate the required sensitivity for detection of the predicted s pectral amplitude and show that the allowed region of our parameter space l eads to a signal smaller (by one 1.5 orders of magnitude) than the advanced laser interferometric gravitational wave observatory sensitivity at a freq uency of 0.1 kHz. The maximal signal in our context, is expected in the GHz region where the energy density of relic gravitons in critical units (i.e. , h(0)(2)Ohm(GW)) is Of the order of 10(-6), roughly eight orders of magnit ude larger than in ordinary inflationary models. Smaller detectors (not nec essarily interferometers) can be relevant for detection purposes in the GHz frequency window. We suggest or speculate that future measurements through microwave cavities can offer interesting perspectives. [S0556-2821(99)0272 2-8].